Record in and out jacks?

A preamp's PRE-OUT/MAIN IN, with LINKS is a bit different. It's a joint in the output wire

They are an external LINK in the signal chain, that MUST be connected for the signal to move back into/thru/out of that unit.

either

The U shaped factory LINKS

or

you go out thru something, back in, that something completing the link.
..............................

you can remove the link, use the pre-out (nothing into main in), but then the signal has to keep going thru something else to get to the amp/speakers.

 

yes, you can use them for other equipment

EQ: equalization happens somewhere for both tape and lp. these are labeled tape, or record: but there is no eq involved in the preamp ’tape loop’ itself: the tape eq or any processing happens elsewhere.

OUT: they are line level, same as pre-out, send line level out to something

IN: use for any line level source in.

LISTENING: vintage, or new: various ’monitoring’ schemes/switches exist, make sure you know what you have or will have, how it works.

SIGNAL STRENGTH (in round numbers):

check the ’line’ specs of your unit(s). old days, pre-amps didn’t exist. amps were designed for A LINE LEVEL OF 1 volt in. pre-amps came about to boost new magnetic tape head’s and NEW magnetic cartridge’s weaker signal strength up to the 1 volt needed by existing AMPS. later: even smaller signal strength from low output MC cartridges need a pre-pre amp.